Need support for MacOS

[pedantix]

We have slated adding images to the project, and since Zello's Cocoa team primarily does iOS development we may accidentally pigeon hole ourselves into UIKit. The consequence of this is presenting users from easily using our SDK on macOS and iOS. Certainly, project Catalyst is a workaround for this however some potential SDK users may be veteran Cocoa developers and not thrilled with the idea of having to learn CocoaTouch to write a macOS app. As we want to encourage as widespread of adoption as we can we should endeavor to make sure our framework compile for MacOS/iOS with feature parity.